Typically, for doing the wash by using a washing machine, laundries and a detergent are put into the washing machine, a washing course is set, and then a washing start button is pressed to run the washing machine. However, there are many cases where busy contemporaries miss a washing chance, and where doing the wash at once on weekend rather than several times on weekdays. In particular, when a laundry weight is not periodically checked, the washing chance is apt to be missed, and when the laundry is excessively piled up, washing takes a long time. In addition, since the washing is not timely done, there are many cases of knowing that the washing is not done at the time of going to school or going to work.